Key Points
• Former Wisconsin OB-GYN Dr. Frederick Dettmann is accused of using his own sperm to inseminate fertility patients without their knowledge or consent.
• A genealogy DNA test conducted in 2024 allegedly linked one patient's son to Dettmann and revealed connections to multiple half-siblings.
• Attorneys representing the family say they plan to file a civil lawsuit and are seeking other former patients who may have undergone similar procedures.
A former Wisconsin OB-GYN who practiced infertility medicine is accused of using his own sperm to inseminate fertility patients without their knowledge or consent, according to attorneys representing a former patient and her family. The allegations emerged after a 2024 genealogy DNA test reportedly linked the woman's son to Dr. Frederick G. Dettmann rather than the anonymous donor she said was promised during treatment in the early 1980s.
Dettmann, who practiced obstetrics, gynecology, and reproductive medicine in Whitefish Bay and the Milwaukee area for decades, is alleged to have fathered children born through donor insemination procedures. Attorneys with Cannon & Dunphy say they plan to file a civil lawsuit and believe additional women may have undergone similar treatment.
According to attorney Al Foeckler of Cannon & Dunphy, Mary Ellen Lukezich underwent artificial insemination in the early 1980s after being told the donor sperm would come from an anonymous medical student.
In December 2024, her son, Joseph Laedtke-Heider, underwent genealogy DNA testing that, according to the family's attorneys, revealed biological links to multiple half-siblings and traced their parentage to Dr. Frederick G. Dettmann.
Laedtke-Heider said the discovery was life-altering, stating that his "entire identity" had been built on false information about his biological father.
Attorneys representing the family say the findings suggest other women may have undergone similar procedures and are encouraging former patients of Dettmann to come forward.
Artificial insemination requires patients to be informed about the source of donor sperm and to consent to the procedure based on that information.
In this case, attorneys allege Mary Ellen Lukezich agreed to treatment using sperm from an anonymous medical student but later learned through DNA testing that her son's biological father was Dr. Frederick G. Dettmann.
Attorney Al Foeckler of Cannon & Dunphy told CBS 58 that the alleged conduct represented "the ultimate betrayal," adding that the physician "secretly impregnated his patient with his own sperm, without her knowledge, without her consent, and against her understanding of her care."
The family's legal team says it plans to pursue a civil lawsuit alleging battery and is encouraging other former patients who underwent donor insemination procedures with Dettmann to come forward.
Dr. Frederick G. Dettmann has denied the allegations through his attorney. In statements provided to CBS 58 and FOX6 News, his legal counsel said the retired board-certified OB-GYN has no independent recollection of the individuals involved and noted that the events described allegedly occurred nearly five decades ago.
His attorney stated that Dr. Dettmann was never sued, disciplined, had his medical license challenged, or faced ethical complaints during his medical career. The statement further said that "Dr. Dettmann has no independent recollection of the individuals making these allegations and is unaware of any evidence supporting the claims being asserted."
Because of HIPAA and Wisconsin medical confidentiality laws, the attorney said Dr. Dettmann could not comment on specific patient care. Separately, the Whitefish Bay Police Department told local media outlets that there are currently no active investigations related to the allegations.
Also see: A Path to Parenthood: The Future of Fertility Treatments Beyond IVF
The allegations against Dr. Frederick G. Dettmann have renewed discussion about informed consent, donor transparency, and accountability in reproductive medicine.
According to Cannon & Dunphy attorney Al Foeckler, DNA results linked Joseph Laedtke-Heider to multiple half-siblings who reportedly share the same biological father, leading the family to question the donor information provided during fertility treatment.
Dr. Dettmann has denied wrongdoing through his attorney.
(Rh/TP)
